Trump’s US-Mexico border wall ‘could cost $31bn’

Building a wall between the US and Mexico could cost as much as $31bn (£25bn), casting fresh doubt on the viability of incoming US president Donald Trump’s pet project.

Trump, who becomes president today (Friday), announced his intention to build a wall between Mexico and the US when he launched his presidential campaign, saying “nobody builds walls better than me, believe me, and I’ll build them very inexpensively … mark my words.”

But according to a new estimate drawn up by cost consultancy Gleeds for Building, the wall’s price tag could hit as much as $31bn.

The estimate is more than double the highest figure put on the project by Trump’s team, and is also higher than an independent analysis of the cost by US firm Alliance Bernstein, which said the project was widely expected to cost more than “$15bn and perhaps as much as $25bn”.

Gleeds’ analysis estimates the wall would require 44 million cubic yards of concrete, at a cost of $3.96bn, and 9 million tonnes of steel, at a cost of $6bn. Nearly $900m would have to be spent building roads so that construction materials could be brought to the remote sites, and $1.2bn spent on land removal. The cost of professional fees and the impact of “surge pricing” given the demand increase generated by the project, is estimated at over $6bn.

However, Gleeds made clear the price was a very broad estimate – given both the huge number of variables in the project and its massive complexity.

While Trump has made varying statements about the cost, height, length and nature of the wall, his most expensive estimate of the cost has been $12bn. While pledging to make Mexico pay for the wall, he has recently admitted that the US is likely to pay for construction up front while seeking to recover costs from Mexico afterwards.

For the purposes of the estimate, Gleeds assumed the wall will be built to a length of 1,000 miles - the number Trump has most commonly used - with the rest of the 1,889-mile US-Mexico border to be protected by natural barriers such as mountains and rivers. The estimate assumes the wall will be built predominantly of pre-cast concrete, be 50ft high, and will run 10ft underground to deter tunnellers.

Richard Steer, chairman of Gleeds, said: “The idea of building a 1,000-mile wall which is designed to be impenetrable is something that may well come back to haunt the president. There are simply too many imponderables to be able to offer an effective solution. Challenge areas not yet fully examined … include height, depth, width and materials, as well as ensuring that there are sufficient alarms and well-resourced … teams on hand to police the new structure.

“All in all this idea would appear to have made a highly effective and eye catching election tweet but a pretty unrealistic tendering opportunity as currently reported.”

Regarding the firm’s cost estimate, a Gleeds spokesperson added: “The construction of Trump’s wall is an ever-changing brief which makes it almost impossible to provide an accurate costing with so little by way of fixed and realistic proposals.

“However, by applying normal principles and the kind of approach that one might adopt, such a project could be within these parameters. Gleeds would, however, insist on a strong and robust client brief before advising anyone to embark on such a currently ill-defined, mammoth high-profile initiative of this kind.”

Trump’s wall - Gleeds’ cost estimate

Material/cost area

Unit

Volume

Price

Concrete (pre-cast)

yd³

44m

$3.96bn

Steel (mild)

tonne

9m

$6.12bn

Labour

Working years

200,000

$7bn

Security system

ft

5.3m

$1.1bn

New roads for trucks to deliver materials

yd²

1.8m

$880,000

Land removal

yd³

24.4m

$1.2bn

Design, engineering and legal fees. Surge pricing included

$6.1bn

Prelims

$2.6bn

Risk

$1.4bn

Total

$30.4bn

Inflation (2016-2020)

$607,755

Final total

$31bn

Editor’s note: Due to a production error, an earlier version of this story was published giving the final total in the cost table as $30.1bn. Building would like to make clear this error occurred during the article production cycle and was not introduced by Gleeds